Art of displacing air in the packaging of products by the use of bubbles of inert gas



2.433.071 PACKAGING OF PRODUCTS SE OF BUBBLES 0F INERT GAS Filed June 17, 1944 Law JLESZcvcnaon A. E. STEVENSON NG AIR IN THE ART OF DISPLACI Dec. 23,

Patented Dec. 23,1947 r ART OF DISPLACING Am IN THE PACKAG- ING OF PRODUCTS BY THE USE OF BUB- BLES OF INERT GAS Arthur E. Stevenson, Chicago, 111., assignor to Continental Can Company, Inc., New York, N. Y., a corporation of New York Application June 17, 1944, Serial No. 540,877 7 Claims. (Cl. 226-458) UNITED STATES .PATENT OFFICE 2 In packaging products, it is often desirable to space again, whereby air is again present in the exclude air from the container as an incident of head space. the packaging and sealing. When the gas is incorporated in a foam, and

It has heretofore been proposed to employ this foam is delivered into the head space for evacuation of the air, followed by admission of 5 fillin h m e f m behaves as a l fl s a replacement gas prior to closure, as well as closliquid rather than as a vap0r and i sliming while the container is under reduced presciently heavier than air to d1splace the air from sure; likewise, to employ jets or currents of gases the head space: and the foam can be caused to and vapors for eliminating air from the conremain in place in the head space until the can tainers as an incident of filling and closing; and is 0105611 The compressibility of t s in the to provoke th f r ti f f am within the foam permits the seating and sealing of a. cover filled contain r b causing a gas to bubble without difliculty, as compared with the troubles through a liquid content in the contain of attempting to close and seal acontamer which The present invention is concerned with the a h mp1ete1y filled Wlth hqlhd; production r a f externally of the container, It is further a part of the present invention to and the delivery of this foam into the filled conmtmduce to t hquid whlch is mm the e tainer for displacing air from the head space substhhce m the h ot a Surface tension thereof, and with the closing of the container cohtr 011mg agent whtch h assure sta'hthty to while the head space is occupied by Such a foam the foam over the time interval incident to the In practice, it is preferred to employ for the plum? and ctosmg of the cover foam-producing liquid a, material which is An luustra'tlve 9 of apparatus for practilc' natural to the product to be packaged; and to mg the procedure is shown in the accompanying employ for the gas an inert or non-oxdizing subgx fi drawing a liquid reservoir m is gg g sgfi 2: mtrogen carbon 5 plied with a liquid through a pipe II and under control of a float valve l2 whereby a substantially In packaging products, the containers are ordinarily not completely filled, and a small space zgg b hqmd level Is mamtamed m the reser ff g at thefop zh is hh t termed the A restricted conduit l5 connects the reservoir ea F T ptovlswh 1S necessary e" In with a foam chamber l6 which includes closcause, if the container 15 completely filled, there mg walls and a partition which is positioned 1s interference with the sealing operation. At essentially horizontally f dividihg the m the time of closing, this head space contains some chamber t a lower compartment Is d an and usually some Vapor from e pmdhct upper compartment [9. This partition plate I! being packaged, the total vapor pressure being is porous so that it permits movement of gas that of the atmhsphetei and Wlth the Parttal I therethrough: but the pores are of such small Pressure of h depehthhg i the temperature of individual size that liquid is essentially prevented the Pmduct 1n t hohtamer, and the actual from any downward flow. Therefore, the flow of Vh1me 01 Such helhg dependent upon Partial liquid from the reservoir l0 through the restricted upon the Volume of the head 40 conduit l5 leads to the formation of a thin layer T s al houl e e o as C p t y a f liquid on the upper surface of the porous partipossible, because the oxygen thereof may cause tion plate ll. changes in the product with resultant undesirable A source f inert gas under pressure is c a g s n fla n 501116 instances, nected to-the lower compartment I8 of the foam color. Further, if the container includes a metal ha ber, illustratively by the employment of a such as iron or t n-P the oxygen may cause conduit 20 for such gas, and with inclusion of a corrosion of the interior of the container, particucontrol valve 1 whereby the t or mm of lar y ad nt t d p In employing l ts flow may be varied. This lower compartment is or currents of inert gases such as stea n trogen is also preferably provided with a. bottom dis- Or c r n dioxide. J' t Previous to e closing. charge conduit 22 including a shut-off valve 23. difliculty has been encountered in effectively re- Th upper compartment 9 of t foam cham- P cing the air because of the relatively low her is normally larger than the lower compartn y an hi h molecular velocity of such ment l8, and leads into a discharge conduit 2 gases: and, in addition, diffusion and aircurat its top, this conduit being continued to rents tend to carry these gases out of the head nozzle end 26 positioned over a container C rest sauce or juice, etc.

When a filling F of foam has totally occupied the head space of the container C, this container is moved to a position C upon platform P, being provided meanwhile with tion C, tinues in the same fashion,

When the packaged material 7 preferred likewise to provide orange juice as the quid entering through the pip ll, wherewith the hquid position of the foam is natural to the is orange juice, it

gallon gave satisfactory cold and hot water solutions. Sodium alginate in the proportion of 1 ounce per gallon of water is very satisfactory; and as low as /2 be used. Gum arabic in the proportion 01' 1 ounce can be employed. In general, the substances for are non-toxic and preferably edible, and are present in quantities of 0.1 to 1.0 percent of the weight of the water.

It is preferred to have the foaming liquid prostability, to ensure that form until the closure and it will be underalbumin per gallon thereof.

3. The method tainer and eliminating air from the head space displace air therefrom.

4. The method substantial absence of air, which comprises preparing an aqueous foam-forming liquid for form- 6. The method of packaging a, material in a of packaging a foodstuif in the prises passing an inert gas into a foam-forming liquid outside of the container for providing a supply of foam, delivering a sufficient quantity of foam into the head space of the container to totally displace the air therein, and then sealing the container with the foam filling the voids thereof.

ARTHUR E. STEVENSON.

REFERENCES CITED The following references are of record in the file of this patent:

- UNITED STATES PATENTS Number Name Date Stevenson et a1 Nov. 9, 1943 

